In-Device Displacement Sensing

In some settings, laparoscopic or endoscopic surgical instruments may be preferred over traditional open surgical devices to minimize the size of the surgical incision as well as post-operative recovery time and complications. Consequently, some endoscopic surgical instruments may be suitable for placement of a distal end effector at a desired surgical site through the cannula of a trocar. These distal end effectors may engage tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, stapler, clip applier, access device, drug/gene therapy delivery device, and energy delivery device using ultrasound, RF, laser, etc.). Endoscopic surgical instruments may include a shaft that extends proximally from the end effector to a handle portion, which is manipulated by the clinician, or alternatively to a robot. Such a shaft may enable insertion to a desired depth and rotation about the longitudinal axis of the shaft, thereby facilitating positioning of the end effector within the patient. Positioning of an end effector may be further facilitated through inclusion of one or more articulation joints or features, enabling the end effector to be selectively articulated or otherwise deflected relative to the longitudinal axis of the shaft.

Examples of endoscopic surgical instruments include surgical staplers. Some such staplers are operable to clamp down on layers of tissue, cut through the clamped layers of tissue, and drive staples through the layers of tissue to substantially seal the severed layers of tissue together near the severed ends of the tissue layers. Such endoscopic surgical staplers may also be used in open procedures and/or other non-endoscopic procedures. By way of example only, a surgical stapler may be inserted through a thoracotomy and thereby between a patient's ribs to reach one or more organs in a thoracic surgical procedure that does not use a trocar as a conduit for the stapler. Such procedures may include the use of the stapler to sever and close a vessel leading to an organ, such as a lung. For instance, the vessels leading to an organ may be severed and closed by a stapler before removal of the organ from the thoracic cavity. Of course, surgical staplers may be used in various other settings and procedures.

The pose (i.e., pitch and yaw) and anvil position (i.e., jaw opening or angle) of the end effectors is an important piece of information when using the endoscopic surgical instruments. Electronically detecting the end effector pose and anvil position may be difficult due to challenges in placing and reading sensors located in the end effectors, e.g., near the components to be measured.

The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.

The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those having ordinary skill in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

For clarity of disclosure, the terms “proximal” and “distal” are defined herein relative to a human or robotic operator of the surgical instrument. The term “proximal” refers the position of an element closer to the human or robotic operator of the surgical instrument and further away from the surgical end effector of the surgical instrument. The term “distal” refers to the position of an element closer to the surgical end effector of the surgical instrument and further away from the human or robotic operator of the surgical instrument. In addition, the terms “upper,” “lower,” “lateral,” “transverse,” “bottom,” “top,” are relative terms to provide additional clarity to the figure descriptions provided below. The terms “upper,” “lower,” “lateral,” “transverse,” “bottom,” “top,” are thus not intended to unnecessarily limit the invention described herein.

Furthermore, the terms “about,” “approximately,” “substantially,” and the like as used herein in connection with any numerical values, ranges of values, and/or geometric/positional quantifications are intended to encompass the exact value(s) or quantification(s) referenced as well as a suitable tolerance that enables the referenced feature or combination of features to function for the intended purpose described herein. For example, “substantially parallel” encompasses nominally parallel structures.

As used herein in connection with various examples of end effector jaw tips, a tip described as “angled,” “bent,” or “curved” encompasses tip configurations in which a longitudinal path (e.g., linear or arcuate) along which the tip extends is non-coaxial and non-parallel with a longitudinal axis of the jaw body; particularly, configurations in which the longitudinal tip path extends distally toward the opposing jaw. Conversely, a tip described as “straight” encompasses tip configurations in which a longitudinal axis of the tip is substantially parallel or coaxial with the longitudinal axis of the jaw body.

depict an example of a surgical stapling and severing instrumentthat is sized for insertion through a trocar cannula or an incision (e.g., thoracotomy, etc.) to a surgical site in a patient for performing a surgical procedure. Instrumentof the present example includes a handle portionconnected to a shaft, which distally terminates in an articulation joint, which is further coupled with an end effector. Once articulation jointand end effectorare inserted through the cannula passageway of a trocar, articulation jointmay be remotely articulated, as depicted in phantom in, by an articulation control, such that end effectormay be deflected from the longitudinal axis (LA) of shaftat a desired angle (a). End effectorof the present example includes a lower jaw(also referred to herein as a cartridge jaw) that includes a staple cartridge, and an upper jaw in the form of a pivotable anvil jaw.

Unless otherwise described, the term “pivot” (and variations thereof) as used herein encompasses but is not necessarily limited to pivotal movement about a fixed axis. For instance, in some versions, anvil jawmay pivot about an axis that is defined by a pin (or similar feature) that slidably translates along an elongate slot or channel as anvil jawmoves toward lower jaw. Such translation may occur before, during, or after the pivotal motion. It should therefore be understood that such combinations of pivotal and translational movement are encompassed by the term “pivot” and variations thereof as used herein. The term “anvil position” as used herein encompasses but is not necessarily limited to the position of the anvil (or anvil/upper jaw) with respect to the staple cartridge channel (or cartridge/lower jaw), or in other words, the jaw opening position, also called “aperture” or jaw angle. The term “pose” (and variations thereof) as used herein encompasses but is not necessarily limited to the pitch and yaw of the end effector or device. In other words, the term “pose” refers to the angular position of the end effector or device around a horizontal and vertical axis relative to the device shaft. Different devices may have only one angle adjustment (pitch or yaw), two angle adjustments (pitch+yaw), or a third axis adjustment such as the roll or tip roll. The term “stability” of the device is used herein to refer to detecting any change in position or pose of the device.

Handle portionincludes a pistol gripand a closure trigger. Closure triggeris pivotable toward pistol gripto cause clamping, or closing, of anvil jawtoward lower jawof end effector. Such closing of anvil jawis provided through a closure tubeand a closure ring, which both longitudinally translate relative to handle portionin response to pivoting of closure triggerrelative to pistol grip. Closure tubeextends along the length of shaft; and closure ringis positioned distal to articulation joint. Articulation jointis operable to communicate/transmit longitudinal movement from closure tubeto closure ring. Other closure systems may be used, such as using a firing member, such as the cutting edgeof firing beam, for closure rather than a separate closure mechanism.

As shown in, handle portionalso includes a firing trigger. An elongate member (not shown) longitudinally extends through shaftand communicates a longitudinal firing motion from handle portionto a firing beamin response to actuation of firing trigger. This distal translation of firing beamcauses the stapling and severing of clamped tissue in end effector, as will be described in greater detail below.

As shown in, end effectoremploys a firing beamthat includes a transversely oriented upper pin, a firing beam cap, a transversely oriented middle pin, and a distally presented cutting edge. Upper pinis positioned and translatable within a longitudinal anvil slotof anvil jaw. Firing beam capslidably engages a lower surface of lower jawby having firing beamextend through lower jaw slot(shown in) that is formed through lower jaw. Middle pinslidingly engages a top surface of lower jaw, cooperating with firing beam cap.

shows firing beamof the present example proximally positioned and anvil jawpivoted to an open configuration, allowing an unspent staple cartridgeto be removably installed into a channel of lower jaw. As best seen in, staple cartridgeof the present example includes a cartridge body, which presents an upper deckand is coupled with a lower cartridge tray. As best seen in, a vertical slotextends longitudinally through a portion of staple cartridge body. As also best seen in, three rows of staple aperturesare formed through upper deckon each lateral side of vertical slot. As shown in, a wedge sledand a plurality of staple driversare captured between cartridge bodyand tray, with wedge sledbeing located proximal to staple drivers. Wedge sledis movable longitudinally within staple cartridge; while staple driversare movable vertically within staple cartridge. Staplesare also positioned within cartridge body, above corresponding staple drivers. Each stapleis driven vertically within cartridge bodyby a staple driverto drive stapleout through an associated staple aperture. As best seen in, wedge sledpresents inclined cam surfaces that urge staple driversupwardly as wedge sledis driven distally through staple cartridge.

With end effectorclosed, as depicted inby distally advancing closure tubeand closure ring, a firing member in the form of firing beamis then advanced distally into engagement with anvil jawby having upper pinenter longitudinal anvil slot. A pusher block(shown in) located at distal end of firing beampushes wedge sleddistally as firing beamis advanced distally through staple cartridgewhen firing triggeris actuated. During such firing, cutting edgeof firing beamenters vertical slotof staple cartridge, severing tissue clamped between staple cartridgeand anvil jaw. As shown in, middle pinand pusher blocktogether actuate staple cartridgeby entering into vertical slotwithin staple cartridge, driving wedge sledinto upward camming contact with staple drivers, which in turn drives staplesout through staple aperturesand into forming contact with staple forming pockets(shown in) on inner surface of anvil jaw.depicts firing beamfully distally translated after completing severing and stapling of tissue. Staple forming pocketsare intentionally omitted from the view inbut are shown in. Anvil jawis intentionally omitted from the view in.

shows end effectorhaving been actuated through a single firing stroke through tissue. Cutting edge(obscured in) has cut through tissue, while staple drivershave driven three alternating rows of staplesthrough tissueon each side of the cut line produced by cutting edge. After the first firing stroke is complete, end effectoris withdrawn from the patient, spent staple cartridgeis replaced with a new staple cartridge, and end effectoris then again inserted into the patient to reach the stapling site for further cutting and stapling. This process may be repeated until the desired quantity and pattern of firing strokes across the tissuehas been completed.

Instrumentmay be further constructed and operable in accordance with any of the teachings of the following references, the disclosures of which are incorporated by reference herein: U.S. Pat. No. 8,210,411, entitled “Motor-Driven Surgical Instrument,” issued Jul. 3, 2012; U.S. Pat. No. 9,186,142, entitled “Surgical Instrument End Effector Articulation Drive with Pinion and Opposing Racks,” issued on Nov. 17, 2015; U.S. Pat. No. 9,517,065, entitled “Integrated Tissue Positioning and Jaw Alignment Features for Surgical Stapler,” issued Dec. 13, 2016; U.S. Pat. No. 9,622,746, entitled “Distal Tip Features for End Effector of Surgical Instrument,” issued Apr. 18, 2017; U.S. Pat. No. 9,717,497, entitled “Lockout Feature for Movable Cutting Member of Surgical Instrument,” issued Aug. 1, 2017; U.S. Pat. No. 9,795,379, entitled “Surgical Instrument with Multi-Diameter Shaft,” issued Oct. 24, 2017; U.S. Pat. No. 9,808,248, entitled “Installation Features for Surgical Instrument End Effector Cartridge,” issued Nov. 7, 2017; U.S. Pat. No. 9,839,421, entitled “Jaw Closure Feature for End Effector of Surgical Instrument,” issued Dec. 12, 2017; and/or U.S. Pat. No. 10,092,292, entitled “Staple Forming Features for Surgical Stapling Instrument,” issued Oct. 9, 2018.

The features of the present disclosure seek to enable a clinician to quickly and precisely identify a pose (i.e., pitch and yaw) and anvil position (i.e., jaw opening or angle) of an end effector prior to or during a surgical procedure.

In at least one form, a surgical instrument may include a handle, a shaftcomprising a proximal shaft portion coupled to the handle and a distal shaft portion, and an articulation jointconnected to the distal shaft portion. The surgical instrument may further include an end effectorincluding a proximal end coupled to the articulation joint, a distal end, a first jaw member, a second jaw member, wherein one of the first jaw member and the second jaw member is movable relative to the other of the first jaw member and the second jaw member, for example where the first jaw member is a lower jaw(also referred to herein as a cartridge jaw) that includes a staple cartridge, and the second jaw member is an upper jaw in the form of a pivotable anvil jaw. Alternative end effectors may be used that include different movable components.

In some instances, it may be desirable to determine a pose or position of components of the endoscopic device including the end effector. In an example, the pose or position may be used to determine if components of the end effectorhave been deformed or otherwise not in a ground or factory calibrated position (i.e., an initial or known position before any movement or deformation). The pose or position of a component may be determined by identifying a starting pose or position of the component and then detecting subsequent movement or displacement. In addition, these components (articulation joint, first jaw member, second jaw member, etc.) may move relative to one another. Measuring the relative movement between components may allow for a determination of the stability or state of the end effectorand components included therein. Deploying sensors at the end effectorof an endoscopic device to measure the movement presents many technical challenges. When placed in the end effector, the sensors may be exposed to many hazards, both while in-use and in non-surgical handling (such as back-table preparation and shipping). Sensors that rely on a field effect (such as magnetism, Hall-effect, RF, etc.) may also suffer from range limits and non-linearity which must be corrected in subsequent signal-processing. To function, sensors may also be exposed or close to the external envelope of the device, making the sensors vulnerable to damage or interference. In addition, reading the mechanical displacement information from secondary or tertiary moving parts (such as articulation cables running through the shaft of the surgical instrument to control articulation of the end effector) leads to errors and assumptions, because these moving parts may be load-bearing and present accuracy issues as a measurement system (due to friction and compliance).

Embodiments described herein provide sensor(s)located away from the distal end of the endoscopic device that are able to measure movement or displacement of components at the distal end of the endoscopic device, such as, for example, the lower jaw, pivotable anvil jaw, articulation jointand the like. Movement of the components is measured by the sensorsusing a direct mechanical connection to the components. The sensorsprovide a digital, linear signal directly proportional to the desired mechanical characteristic, such as a device pose (pitch, yaw) or anvil position. By moving the sensorsaway from the end effectorand into the shaftand by providing dedicated mechanical connectors, embodiments avoid taking measurements off parts that are not directly connected to the desired quantity to be measured (such as articulation cables or bands) and further avoid making assumptions about the positional relationship.

In an example embodiment, the sensormay be an electromagnetic encoder and is included within a shaftof a surgical stapler device. The electromagnetic encoder detects a position of a scalesuch as a magnet that is mechanically attached to a moveable stapler component, for example by a mechanical connectorsuch as a wire, tape, or filament that leads from the movable stapler component of an end effectorof the surgical stapler device to the scaleand sensorthat are located in the shaft. The direct measurement of the moveable stapler component may be used to verify the stability, pose, or position of the end effectorof the surgical stapler device.

In addition to a more accurate understanding of the position, orientation, or movement of the moveable stapler component or mechanical part, embodiments provide further benefits. The sensing electronics disclosed herein are housed inside the shaftor handle of the device. The sensing electronics may thus be located in “safe” areas of the device where space is not at a premium and away from locations that risk physical damage. As the mechanical connectoris mechanical, there are no difficult passthroughs of electrical signals. This avoids routing electrical signals through tortuous mechanical paths into the distal tip of the end effector. In addition, the mechanical connector(to the component-of-interest) may be provided by thin filaments or wires that are easily routed through the device and robust enough to retain function, even when damaged. Sensorssuch as linear encoder read-heads may be miniaturized and provide several communication options such as single-wire digital, RS-422, quadrature, or analog. The scalemay also be specified for determining absolute measurement. The ability to determine an absolute position of the component allows for power-off of the device without losing the identity of the position of the component on power-on. This feature may eliminate the need to home or reset the component/end effector to a ground or home position.

Referring now to the figures,depicts an example of a system for detecting displacement of one or more mechanical parts.includes a sensor, a mechanical coupling, linkage or connector(for example, a wire), a scale(e.g., a coded section of the connector), a shaft, an articulation joint, and an end effector. Not shown are other components such as a handle attached to a proximal end of the shaft. The shaft, which distally terminates in the articulation joint, is coupled with an end effector. In other words, the articulation jointcouples the end effectorto the shaft. The end effectorincludes a lower jaw(also referred to as a cartridge jaw) that includes a staple cartridge, and an upper jawin the form of a pivotable anvil jaw.

The sensoris configured to sense, detect or read the scaleas the scaleslides past the sensor. The sensormay be fixed or movable. When fixed, the sensormeasures the movement of the scaleas the scalemoves past, through or proximate to the sensor. When movable, the sensormeasures the relative movement of the scalein relation to the sensor. The scaleis included with or physically connected to the movable component to be monitored using a mechanical connector. In application, as the movable component, such as an articulation joint, the lower jaw, or the upper jaw, moves or is displaced, the scalealso moves since the scaleis mechanically connected to the movable component. The sensormeasures the movement by reading the scaleas the scalemoves back and forth. In an embodiment, the optical, magnetic or mechanical indications induce the sensorto generate a signal when an indicator passes by or through the sensor. Measuring the signals may provide an indication of the degree and rate/speed of movement. Pulse width/duration may be controlled by the size of each indication and the size need not be uniform. Using different size indications to create different pulse widths may be used to enable determination of directionality of movement, and when movement reaches a maximum or minimum range, etc. A device controlleror other processing unit, located in the handle (not shown) or shaft, analyzes the movement and provides feedback or information to an operator, such as, for example, a pose, position, or stability of the end effector. During operation, components of the end effectormay be moved, positioned, oriented, posed, and/or articulated. This movement, orientation, pose, and/or articulation may be detected and quantified by the system of.

In, a component of interest, e.g., movable component, is the articulation joint. Alternative components may be measured such as the jaw components (lower jaw, upper jaw), or other features or components of the end effector. The movable component may move a certain distance when the end effectoris articulated or used. The movement of the movable component is translated to the sensorusing a mechanical connectorattached to the movable component.

The mechanical connectormay be provided by a filament, wire, or other tendon-like object, for example a slender threadlike object or fiber. At a distal end of the mechanical connector, the mechanical connectoris attached to the movable component to be measured. The mechanical connectormay be attached, fastened, or joined to the movable component using any known type of attachment, fastener, or jointing process. In an example, the mechanical connectoris soldered to the movable component. The proximal end of the mechanical connectorincludes, or is attached to, a coded section referred to as a scaleas described below. The proximal end of the mechanical connectoris not fixed but may move freely back and forth along the long axis of the shaft(i.e., distally or proximally within the shaft). A housing, channel, and/or guide(s) may be provided that prevents lateral movement of the mechanical connector. In this regard, the housing, channel, and/or guide(s) may isolate the mechanical connectorfrom other moving components of the endoscopic device/shaft.

The mechanical connectormay be made of any material that provides or allows for translation of the movement of the distal end of the mechanical connector(the movable component) to the proximal end of the mechanical connector(the scale/coded section). In other words, when the proximal end of the mechanical connectormoves a certain distance, the distal end of the mechanical connectormoves a similar/same distance and vice versa. The material may have a level of stiffness or compliance so that the mechanical connectordoes not stretch, fold, or deform longitudinally when the mechanical connectormoves back and forth due to the movement of the movable component. In an embodiment, the mechanical connectoris a thin filament made of a metal alloy such as steel or nitinol. The mechanical connectormay be a strip, strand, cable, link, and the like. The mechanical connectormay be, for example, a rigid cable or semi-rigid or semi-flexible wire.

The mechanical connectoris not fixed at one end (e.g., the proximal end) and thus is not under stress. The mechanical connectoris designed to be able to handle the movement of the movable component that the mechanical connectoris attached to and not any additional load. Thus, the mechanical connectormay include a small cross section, for example between 0.1 and 0.3 mm. In certain scenarios, the mechanical connectormay be straight from a distal end of the mechanical connectorattached to the movable component to a proximal end of the mechanical connectorthat includes the scale. In other scenarios the mechanical connectormay be bent, curved, or otherwise not straight in order to avoid other components between the sensorand the movable component. A guide, channel, or sheath may be used to guide the movable component through one or more curves or bends.

depict an example of the movement of the mechanical connector.includes the shaft, the end effector, the mechanical connectorincluding a scale, an articulation jointhaving six rib or disc members-, and six guidesincluding a connectionto a first rib memberof the articulation jointwhere the mechanical connectoris anchored, attached, or connected. There may be fewer or more ribs or disc members-in the articulation joint. Additional guides or channels may be used. Other components such as the connections between the other rib members of the articulation jointare not shown. In, the end effectormay be positioned in a “ground” position. The ground position may be considered a starting position where the end effectorand rib members-of the articulation jointare oriented in line with the shaft. The sensoris configured to read the scaleand determine whether the device is at a ground position. In an embodiment, the ground position and its relationship with the scalemay be defined during a calibration process. The device may identify when the end effectoris directly aligned with the shaft. The sensormeasurement of the scaleat this point may be used as a ground reference point. If the sensorreading of the scaledoes not match the ground reference point, then the end effectoris not in a ground position. Minor adjustments may be made prior to each use to make sure the end effectorstarts at the ground position. Due to various forces on the end effectorsuch as the insertion into a patient or the closing of the jaw, a ground position may not be directly orientated in line with the shaftafter a single use of the device. In another example, the end effectormay be articulated to perform a procedure and then removed from the patient body. After removal, the data from the sensormay indicate that the end effectoris not at a ground position. Due to the articulation, the end effectormay not return to the factory ground position, but rather still be articulated by one or more degrees. The end effectormay be articulated or adjusted by an operator or robot to return to the ground position. Alternatively, if the articulation is known, the end effectormay be used again starting from this alternative starting position.

As described, during a procedure, the end effectormay be articulated in different directions. Using the articulation jointthe end effectormay be articulated, for example up to 65 degrees, up to 110 degrees, or more in relation to the shaft.depicts an example where the end effectorhas been articulated approximately 45 degrees in one direction. When the end effectoris articulated, the distance between the rib members-of the articulation jointincreases or decreases. The result is that since the mechanical connectoris fixed to one of the rib members-of the articulation jointat the distal end of the mechanical connector, the mechanical connectormoves when the end effectoris articulated. The movement of the distal end of the mechanical connectorpulls on the proximal end that includes the scale. The movement of the scale(e.g., the current position of the scalevs a previous reading) is measured by the sensor. A device controllerinputs the sensor data and determines the pose, orientation, position, and/or displacement of the end effector. Multiple mechanical connectorsand sensorsmay be used with different components (or located on different locations of a single component) in order to provide multiple measurements that may be used by the device controller.

As mentioned above, the mechanical connectorincludes a scale(also referred to as a coded strip) at or towards the proximal end of the mechanical connector. The scalemay include one or more tracks that include at least one detectable mark or reference that the sensormay read or detect in order to determine the position or movement of the scale. In an example, the scalemay include optical, magnetic, or mechanical marks on, or embedded in, its surface that help the sensorto determine its current position. The marks/references may be magnetic, optical, or otherwise detectable by the sensor.depicts an example of different scales. Scales may include one or more tracks.includes a scale with just an incremental track, a scale with an incremental track with a second track including references, a scale with an incremental track with a single reference, and a scale with an incremental track with a second track with absolute references. The marks/references are depicted as examples and may be more complex or detailed in order to provide additional distinctions. The incremental trackincludes a single track with regularly spaced referenced marks. The incremental track with referencesincludes an additional track that includes reference marks. The incremental track with a single referenceincludes an additional track that includes a single reference such as a ground reference. The incremental track with absolute referencesincludes an additional track that provides various unique references. Each of the marks/references may be offset from each other by a certain distance (such as an incremental track) or the marks may be offset by varying distances (such as in an absolute track). One or more tracks may be used depending on the sensor. In one embodiment, more than one sensorsmay be used to read different tracks on the scale. In an embodiment, the scaleis or includes a magnetic code, an optical code, or a mechanical code that provides the marks/references. The scaleis read or detected by a sensorthat is located in the shaftof the device. The sensoris configured to read the scaleas the scalemoves back and forth due to movement of the mechanical component.

In an embodiment, the sensoris a linear encoder. As the scaleslides past a fixed encoder read head, the linear encoder reads the scaleand determines the amount the scalemoved. The scalemoves back and forth along a long axis (linearly) of the shaft. The sensormay be able to detect a speed, a distance, a direction, and/or a displacement of the scale. In an embodiment, the sensormay be an absolute linear encoder or an incremental linear encoder. As described above,depicts various scales including incremental tracks and absolute tracks. An absolute linear encoder may accurately determine a current position by reading the unique reference marks. When the sensorreads a mark, the resulting signal or data indicates a unique position on the scaleand thus its absolute position. An incremental linear encoder detects a position offset relative to specific points. The marks on the scalemay be identical to each other. With an incremental encoder, the sensoris configured to determine a relative distance moved but not an absolute position. When the sensoris turned off, the latest location status information disappears. Additional special markings or labels such as reference or starting marks may be used. In one example, origin or zero point markings may be used. If the device controllercan identify a reference or starting location and a distance moved from that location, the device controllermay be able to determine a current position of the end effectorby comparing the two. In the example of the incremental track with a single reference, the single reference may indicate a ground or factory calibrated position. If the scaleand sensorare not lined up so that the sensorreads the ground reference, the end effectoris thus not at a “ground” position.

In an embodiment, the sensoris a magnetic linear encoder that uses a magnetic reader head for analyzing changes in magnetic fluxes for displacement analysis. In this embodiment, the scaleincludes a set of poles (north and south) that are magnetically coded. The poles are arranged in a specific way depending on the type of scale(incremental or absolute). When the sensorpasses over each pole on the magnetic scale, the sensorreads current changes in the magnetic fields. For a magnetic linear encoder, the sensormay be a Hall sensor.

In an embodiment, the sensoris an optical linear encoder that uses light beams or lasers as a signal. In this embodiment, the scaleincludes transparent (clear) or opaque areas as marks. Using an optical linear encoder may provide linear measurements with the greatest accuracy and high resolution but has certain drawbacks. Dust or other particles in a gap between the measuring surface and sensoras well as mechanical shocks and vibrations may significantly affect the accuracy. The linear encoder may include protection to prevent contamination from dust, vibrations, and other conditions. The sensormay include infrared LEDs, visible LEDs, miniature lightbulbs, and/or laser diodes to generate the signal.

In an embodiment, the sensoris an optical image sensor. In this embodiment, the optical image sensor takes pictures of the scaleas the scalemoves. The device controllercompares the images for displacement. As with the optimal linear encoder, the sensormay include protection to prevent contamination from dust, vibrations, and other conditions.

The scalemay include or provide an index or reference mark providing a datum position along the scalefor use at power-up or following a loss of power. The incremental track with a single referenceas depicted inis an example of a such a reference mark. The index or datum allows the system to identify a position of the scalewithin one, unique period of the scale. The reference mark may include, for example, a single feature on the scale, an autocorrelator pattern (for example a Barker code) or a chirp pattern. In addition, distance coded reference marks (DCRM) may be placed onto the scalein a unique pattern allowing a minimal movement (typically moving past two reference marks) to define the read head's position. Multiple, equally spaced reference marks may also be placed onto the scalesuch that during installation or calibration, the desired mark may either be selected or unwanted marks deselected.

Signals from the sensorare transmitted to the device controllerand/or another computing device. The device controllerincludes a processor and a memory storing program instructions, which when executed by the processor, causes the processor to perform one or more aspects of the process. The processor computes at least one transfer function that provides a translation of an electrical signal produced by the sensorand the movement. The at least one transfer function may be a first-order equation or use a lookup-table for example. The device controllermay be configured to analyze the signals from the sensorand determine at least one of a position, pose, displacement, or orientation of a component of interest and/or the end effector.

The device controllermay be configured to use a predetermined algorithm to convert the sensor'sreading to a useful value, such as a current yaw-angle. In an example with multiple mechanical connectorsthe yaw and pitch may be measured separately by two different sensors, and these encoder-count readings are converted to an angle indicating the actual angular position. For an encoder, the device controllermay be configured to convert the number of counts from zero at the yaw sensor to an angular value of yaw. Various conversions might be used. For example, a simple linear equation (yaw angle=m (counts)+b) may be used or a more sophisticated function-such as piecewise-linear fit, a polynomial fit, or a lookup-table may be used.

The device controllermay be configured to display a value, such as a current yaw-angle, to the user. Alternatively, or additional, the device controllermay be configured to use the value internally. For instance, the device controllermay feed the value back to the control system to correct a position of the tip to the desired position.

While being able to determine the position, pose, displacement, stability, or orientation of a single component of interest is useful, a better understanding may be provided by multiple sensorsdetermining the displacement of multiple components of interest.

depicts an example of an embodiment where two sensors,are used to measure a pitch and a yaw of the end effector. The system ofincludes a first sensorand a first mechanical connectorthat is attached to a first positionon an articulation joint. As depicted, the first positionon the articulation jointis a position on the articulation jointclosest to the end effector. Another position on the articulation jointmay be used. The system ofalso includes a second sensorand a second mechanical connectorthat is attached to a second positionon the articulation joint. The connectors,are attached to the same rib or disc member of the articulation jointin, but may be attached to different components. Each mechanical connector,includes its own scale,that is read by the respective sensors,. When the end effectoris articulated or moved, the articulation jointmay move. The two positions (first positionand second position) may move different distances depending on the type of movement of the end effector. The movement of each of the positions,is translated to movement of the respective scales,by the mechanical connectors,. The two sensors,read their respective scales,and transmit a signal to the device controller. The signals may be related to the yaw or pitch movement of the end effector. For example, the first sensorand respective first mechanical connectorand first scalemay read a yaw movement of the end effectorwhile the second sensorand respective second mechanical connectorand second scalemay read a pitch movement of the end effector. The device controlleranalyzes the signals to determine a position, pose, displacement, or orientation of the end effector.

depicts another example of an embodiment where a single sensor is used with two mechanical connectors. The system ofincludes a single sensorthat is attached to a first mechanical connectorthat is attached at a pointto a first mechanical component, here the upper jaw. The first mechanical connectordoes not include a scalebut rather is attached to the sensorat a distal end of the sensor(i.e., the proximal end of the first mechanical connectoris attached to the distal end of the sensor). The system offurther includes a second mechanical connectorthat is attached at a pointto a second mechanical component, here the lower jaw. The second mechanical connectorincludes a scalethat is read by the sensor. In operation, the system measures the differential movement of the two mechanical components,. For example, if the first mechanical component is the pivotable anvil jaw(upper jaw member) and the second mechanical component is the lower jaw, then the sensormeasures the differential movement of the pivotable anvil jawand the lower jaw. If the pivotable anvil jawmoves and the lower jawdoes not, the sensorwill detect movement. If the pivotable anvil jawmoves and the lower jawmoves the same amount, then the sensorwill not detect any movement as the sensor would read the same location on the scale. This type of differential analysis may be used in the example of a combination where there is no differential movement detected when the entire end effectoris articulated but there is differential movement when the jaw angle changes due to the pivotable anvil jawmoving and the lower jawnot moving. If there is movement detected, the jaw angle may be determined to have changed. If the only movement is a change in the jaw pose, then there may be no movement detected as the two components (pivotable anvil jaw, lower jaw) move in unison. If the jaw pose and the jaw angle change, movement will be detected.

The embodiments ofandmay be combined such that the system ofmay also be used to measure one aspect of the movement of a component of interest of the end effector. Another fixed sensormay be used to measure the movement of one of the mechanical connectors of. The system ofmay thus be used with the additional sensor to measure one aspect of the movement, e.g., a pitch or yaw of the end effector, while another sensor such as a sensorinmay be used to measure another aspect of the movement, for example the other of the pitch or yaw of the end effector.

depicts another embodiment that uses a fiber optic wireinstead of a mechanical connector. The fiber optic wireruns from a sensorlocated in the shaftto a location near or at a part of interest, for example, the pivotable anvil jaw. In this example, the fiber optic wireruns along a longitudinal axis of the device shaft, which reads an encoder patternetched on a back surface of the pivotable anvil jawto detect the position/pose of the pivotable anvil jaw. The patternis visible by the signals emitted from the fiber optic wirewhen looking at the proximal end of the pivotable anvil jawaxially to the shaft. When the pivotable anvil jawmoves, the encoder patternmoves which is detected by the signals from the fiber optic wire. Additional sensors (additional rotary encoders or hall effect sensors) in the shaftmay be provided to detect the location of the closure handle to establish and input/output relationship.

During application, it will be appreciated that as a user urges the instrument into a surgical region, it may be desirable to approach the tissue to be clamped, stapled, or cut, from a particular angle. For instance, once the end effectorof instrument is inserted through a trocar, thoracotomy, or other passageway for entering a surgical area, the tissue that the user wishes to target may be positioned out of reach or at an askew angle in relation to end effectorthat is aligned with the shaft. Thus, it may be desirable for portions of instrument, such as the end effector, to articulate such that the user can position the pivotable anvil jawand the lower jawof the end effectorto squarely or perpendicularly clamp against a vessel or other tissue.

When the end effectoror portions thereof are articulated or moved, the movement is translated back to sensors in the shaftby the mechanical connector. The pose, orientation, alignment, and/or position of the end effectormay be determined by the device controllerby analyzing signals from the sensorthat is located in the shaftand that is configured to read a scaleat the proximal end of the mechanical connector. In another use, the sensormay read the scaleto determine if the end effectoris at a ground position.

In an alternative embodiment, the mechanical connectormay be combined with a load-bearing member (i.e., using an articulation cable to move the encoder/sensor member). In this case, a transfer-function may ignore or compensate for friction/compliance of the mechanical connectorto the mechanical component.

The following examples/clauses relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples/clauses are not intended to restrict the coverage of any claims that may be presented at any time in this application or in subsequent filings of this application. No disclaimer is intended. The following examples/clauses are being provided for nothing more than merely illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in numerous other ways. It is also contemplated that some variations may omit certain features referred to in the below examples/clauses. Therefore, none of the aspects or features referred to below should be deemed critical unless otherwise explicitly indicated as such at a later date by the inventors or by a successor in interest to the inventors. If any claims are presented in this application or in subsequent filings related to this application that include additional features beyond those referred to below, those additional features shall not be presumed to have been added for any reason relating to patentability.

It should be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The above-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.